Two knowledge items are sometimes associated with each other through manual or automated techniques. Knowledge items are anything physical or non-physical that can be represented through symbols and can be, for example, keywords, nodes, categories, people, concepts, products, phrases, documents, and other units of knowledge. Knowledge items can take any form, for example, a single word, a term, a short phrase, a document, or some other structured or unstructured information. Documents include, for example, web pages of various formats, such as HTML, XML, XHTML; Portable Document Format (PDF) files; and word processor and application program document files. For example, a knowledge item, such as, content from a document, can be matched to another knowledge item, such as, a keyword or advertisement. Similarly, a knowledge item, such as, a document, may be associated with another document containing related content so that the two documents can be seen to be related.
One example of the use of knowledge items is in Internet advertising. Internet advertising can take various forms. For example, a publisher of a website may allow advertising for a fee on its web pages. When the publisher desires to display an advertisement on a web page to a user, a facilitator can provide an advertisement to the publisher to display on the web page. The facilitator can select the advertisement by a variety of factors, such as demographic information about the user, the category of the web page, for example, sports or entertainment, or the content of the web page. The facilitator can also match the content of the web page to a knowledge item, such as a keyword, from a list of keywords. An advertisement associated with the matched keyword can then be displayed on the web page. A user may manipulate a mouse or another input device and “click” on the advertisement to view a web page on the advertiser's website that offers goods or services for sale.
In another example of Internet advertising, the actual matched keywords are displayed on a publisher's web page in a Related Links or similar section. Similar to the example above, the content of the web page is matched to the one or more keywords, which are then displayed in the Related Links section, for example. When a user clicks on a particular keyword, the user can be directed to a search results page that may contain a mixture of advertisements and regular search results. Advertisers bid on the keyword to have their advertisements appear on such a search results page for the keyword. A user may manipulate a mouse or another input device and “click” on the advertisement to view a web page on the advertiser's website that offers goods or services for sale.
Advertisers desire that the content of the web page closely relate to the advertisement, because a user viewing the web page is more likely to click on the advertisement and purchase the goods or services being offered if they are highly relevant to what the user is reading on the web page. The publisher of the web page also wants the content of the advertisement to match the content of the web page, because the publisher is often compensated if the user clicks on the advertisement and a mismatch could be offensive to either the advertiser or the publisher in the case of sensitive content.
Various methods have been used to match keywords with content. Most of these methods have involved a form of text matching, for example, matching the keywords with words contained in the content. The problem with text matching is that words can relate to multiple concepts, which can lead to mismatching of content to keyword.
For example the term “apple” can relate to at least two concepts. Apple can refer to the fruit or the computer company by the same name. For example, a web page can contain a news story about Apple Computer and the most frequently used keyword on the web page, in this case “apple”, could be chosen to represent the web page. In this example, it is desirable to display an advertisement relating to Apple Computer and not apple, the fruit. However, if the highest bidder on the keyword “apple” is a seller of apples and if the keyword “apple” is matched to the web page, the advertisement about apples, the fruit, would be displayed on the web page dealing with Apple, the computer company. This is undesirable, because a reader of the web page about a computer company is likely not also interested in purchasing apples.
Mismatching of knowledge items, such as keywords, to content can result in irrelevant advertisements being displayed for content. It is, therefore, desirable to understand the meaning of knowledge items.